1. Field of the Invention
This invention relates to a spectrofluorometric apparatus for obtaining spectral image information, wherein a sample is exposed to a laser beam, which stimulates and causes the sample to produce fluorescence, and the spectrum of the fluorescence produced by the sample is measured for each point on the sample.
2. Description of the Prior Art
Various types of spectrometric apparatuses for measuring spectra of light, which is to be measured, have heretofore been used widely. As one of such spectrometric apparatuses, a Fourier spectrometric apparatus is known. With the Fourier spectrometric apparatus, the light to be measured is caused by an interferometer to interfere, and the brightness and darkness of the light, which have been produced by the interference, are detected as a signal. The detected signal is then subjected to Fourier transformation, and the spectrum of the light to be measured is thereby measured. Also, research has been carried out to develop Fourier spectrometric techniques for obtaining spectral image information, wherein a spectrum of light produced by an object having two-dimensional spread is measured for each point on the object by utilizing the Fourier spectrometric apparatus. Several types of such Fourier spectrometric techniques have been proposed as described in, for example, the magazine "Laser Kenkyu" (Laser Research), Vol. 15, No. 10, 21 (1987).
Also, an apparatus has been proposed, wherein a sample constituted of a fluorescent substance is exposed to a laser beam, which stimulates and causes the sample to produce fluorescence, and the spectrum of the fluorescence produced by a single point on the sample is measured. Further, an apparatus has been proposed, wherein a sample, which is constituted of a fluorescent substance and has two-dimensional spread, is scanned with a laser beam, which stimulates and causes the sample to produce fluorescence, and the intensity of the fluorescence produced by each point on the sample is measured, image information of the sample being thereby obtained.
As for a sample, such as a living body sample, which inhomogeneously contains a plurality of kinds of fluorescent substances, it is often desired that the spectrum of the fluorescence, which is produced by the sample when the sample is exposed to stimulating rays, can be measured for each point on the sample, and two-dimensional spectral image information of the sample can thereby be obtained. However, no apparatus has heretofore been provided which is capable of carrying out such spectrofluorometry for obtaining spectral image information.